Wednesday, April 15, 2009

A common axiom in gardening is putting the right plant in the right place. Where bamboo is concerned, most people think that the only appropriate location is somewhere on the far side of hell. Bamboo is cherished and ardently defended as a vigorous landscape screen by some, although it is usually cursed as an invasive, unstoppable menace by most others, especially irate neighbors who find spikes and spears shooting up in their lawn and garden beds.

There are more than 750 species of bamboo plants which have been introduced to North America from Asia, the Caribbean, and Latin America. Most of these woody grasses (yes, they are actually grasses!) fall within the genera Bambusa, Pseudosasa, and Phyllostachys, and are renowned for growing upwards of 16 to 40 feet, with a cane or “culm” diameter ranging from one to six inches. Many also experience a general die-back after about a dozen years, usually after flowering, which will leave a dead, yellowed bamboo jungle, until new growth repopulates the grove.

Some species are considered “clumping,” which are generally well-behaved, while the more insidious specimens are called “running bamboos,” which will swiftly produce an impenetrable and monocultural thicket as they exert their own manifest destiny. Among the most commonly sold, planted, and (ultimately) loathed of runners is Golden Bamboo (Phyllostachysaurea).

These exotic invasive bamboos have caused feuds just shy of the infamous Hatfield and McCoy dust-up. Lawsuits have been filed, bulldozers mobilized, and concrete barriers poured. And yet, for all that, people looking to screen their yards from neighbors continue to plant running bamboos, especially in narrow spaces between properties or along fence lines.

Happily, there are attractive and non-invasive alternatives to bamboo blight, but first we should address how best to control and eradicate these invaders.

To keep bamboos from running, a rhizome barrier should be used. Bamboos very seldom produce seeds, and use rhizomes, or horizontal underground roots, to spread outward. To stop this march, a barrier two-three feet deep is essential, with about two inches rising above the soil surface. Slant the barrier outward near the top to ensure that rhizomes hitting your blockade will grow upward, and not down and eventually under the barrier. Keep an eye out and cut off any roots that attempt to grow over the top. Barriers can be made from metal or concrete, although heavy 60 mil plastic is the most readily available and affordable.

Clumps of bamboo can also be dug out, as the roots are actually quite shallow. Be sure to remove any and all pieces of the rootstock, including wayward rhizomes, and keep an eye out for future incursions.

A somewhat easier approach is to cut bamboo shoots as close to the ground as possible, and thereafter snip or mow down any new shoots or pesky regrowth. Eventually, you will starve the rootstock and the plant will die, although you will need to patrol the area on a regular basis for a year or so. This technique is best used on bamboo entering your yard from a neighboring property. In fact, some homeowners simply mow down any shoots in their lawns when they cut their grass, and have seen thumb-thick shoots eventually replaced by pencil-thin sprouts, just before they disappear altogether.

For quicker, more thorough results, Jan Ferrigan, an invasive plant program manager in Virginia, recommends cutting down bamboo shoots and applying Roundup or a similar glyphosate herbicide directly inside the now-open stem, and painting the outer surface of the culm. Jan suggests carefully using the herbicide at a 25 percent concentrated solution, not the typically diluted two percent used for routine spraying. And fall is the usually recommended time for application.

Naturally, the best solution is not to plant exotic bamboos at all. And the finest alternative is, not surprisingly, a native bamboo. Generally called canebrake bamboo (Arundinariagigantea), or southern cane, this species used to cover enormous stretches of riparian “bottom land” from the mid-Atlantic to the Midwest prairies, down through the southeast, and along the Gulf states. Amazingly, before European colonization, native Americans lived among canebrake groves several miles in width, running up to 100 miles in length. Today, there are only scattered patches of these lush thickets.

Homeowners looking for a tall, dense, yet elegant, living fence need look no further. Canebrake can reach 12 to 18 feet or more, with half- to three-quarter inch canes and medium to dark green foliage year-round. However, when shopping around, don’t confuse this species with switch cane (A. tecta), which is smaller, low growing, and more suited as a groundcover plant. And while very few garden centers and nurseries seem to carry canebrake, there are numerous sources online and through mail-order catalogs, with prices ranging from 15 to 25 dollars for one and two gallon containers.

Not interested in bamboo at all? Consider arborvitae (Thuja occidentalis) as an alternate evergreen screen. The cultivar Emerald Green is probably the most popular of standard arborvitae, growing 15-20 feet, with a spread of four-six feet. Its lustrous gem-green foliage is tolerant of cold winters and hot summers, although, as a native of the northeast, it would prefer to be watered during dry periods, and mulched three to four inches deep to retain soil moisture.

Emerald Green can be pruned if or as desired in early spring, and is often considered superior to the much overused Leyland cypress, which could also work as a screen, although it can reach 60 feet and would require substantial pruning to achieve the same effect. Other desirable cultivars include both ‘Nigra,’ which remains dark green even through the winter, featuring a pyramidal form reaching 15-25 feet and five-eight feet wide, and ‘Pyramidalis,’ with softer, bright green needles, growing to 15 feet with a four foot spread.

Another clear winner is Irish juniper (Juniperus communis ‘Hibernica’) with bluish-green foliage, and a columnar form reaching 10-12 feet. This juniper is drought tolerant, with dense upright branches. Some nurseries indicate that it can reach 15 feet with only a narrow two-four foot spread.

There are also numerous species of yews suitable for narrow space screening. All are able to handle heavy pruning and shaping, and contrast their dark green foliage with bright, fleshy red or yellowish-red berries, called arils.

Perhaps most prized of all is Irish yew (Taxus baccata ‘Fastigiata’), which is actually an English or common yew, easily growing from 15-30 feet tall, with a four-eight foot spread. [It is the most commonly grown species in Europe, and has been in use for well over 200 years.] The needles are a striking blackish-green, although other cultivars, such as ‘Fastigiata Aurea,’ while similar in form, actually feature golden foliage on its new spring growth.

Japanese Yews (Taxuscuspidata) generally tend to have a broader spread and lower growth habit, and often quite a slow growth rate. However, cross Japanese and English yews and you’ll find a hybrid (Taxus xmedia) showcasing some of the best assets of each parent. Many of the outstanding cultivars for living screens were developed or discovered on my native Long Island, including several by famed nurseryman Henry Hicks. The specimen bearing his name, Hicks yew (Taxus x media ‘Hicksii’), is columnar in form, 12-20 feet high, and six-ten feet across, with glossy needles, deep green on top and a pale green underneath.

Lastly, Eastern hemlock (Tsugacanadenensis) has long be valued for its light, airy needles and graceful branches, which readily accommodate heavy pruning to create a lush, dense hedge. Left on its own, however, the tree will reach 60 feet with wider spaced branches.

Tuesday, April 14, 2009

Thanks to the luscious, promising warmth of spring and the ongoing inspiration of upcoming Arbor Day, many homeowners and community groups have started to think about tree planting. But choosing just the right tree or trees can be somewhat daunting. Here are some general guidelines, with suggestions from experts around the county.

First, figure out exactly why you want to plant a tree, and what you hope the tree will do for you. After all, there are so many wonderful reasons to plant trees, and so many different species from which to choose.

Many people plant trees for color and beauty, which is not surprising in an area currently dominated by Japanese flowering cherries and dogwoods. However, you might want to consider planting for year-round interest. Instead of loading up your yard with only spring-blooming trees, think about species which flower in mid-summer or fall, or which provide interesting bark, like crepe myrtles, or colorful foliage, like bronze beech or scarlet chokecherry.

For unique color and shape, Bill Rush, the horticultural supervisor for Maryland’s Pope Farm Nursery, recommends the Alaska cedar, a pyramid-shaped specimen with pendulous branches sporting blue-green foliage. Also known as the Nooka Cypress, the tree will eventually grow to between 30 and 45 feet, spreading 15 feet or more, and clearly becoming the show-stopper in a front yard. For a full year of color, Bill suggests the Cornelian cherry, a smaller, multi-stemmed tree with attractive peeling bark, tiny clusters of long-lasting yellow flowers which appear in March, followed by bright red, edible fruits in the summer, and orange-reddish leaves in autumn. The fruits are edible, but very acidic, and best left for the birds.

For brilliant color in smaller spaces, he recommends the ‘Diane,’ ‘Aphrodite,’ and ‘Minerva’ cultivars of Rose-of-Sharon. These are actually thickly-branched large shrubs, growing up to eight feet, with four to six inch-wide flowers in pink, white, and purple, appearing in mid-summer and lasting well into early fall.

Shade is another major goal of tree planting. When summer comes, there is nothing quite so welcome as sitting under the refreshing shade of a mature tree. And when properly placed in the yard, that shade tree can go a long way to reducing summer cooling costs. There are scores of trees common to our area which make perfect shade trees, and perhaps the best suggestion is to simply look around and see what is growing in parks and natural areas nearby. A quick inventory would probably reflect a mix of oaks and poplars, hickories and maples, beech, ash, and gum. However, before you start trying to load a container-grown sycamore into the back of your Porsche, make sure that your tree selection is appropriate to your site.

For example, some tree species, like red maples, will do well in both dry and moist soils, but that is not always the case. Before picking out a tree, talk to the staff horticulturist at a reputable nursery and discuss the type of soil and location you have in mind, or contact your local office of the Cooperative Extension Service at your nearby land grant college.

Of course, some yards already have plenty of shade. In those cases, people often make the mistake of trying to squeeze yet another shade tree under an already dense canopy of mature trees. Do not let a bit of shade, even full shade, dissuade you from your Arbor Day duties. There are plenty of smaller trees and large shrubs ideally suited for your property. At present, the Eastern redbud is bursting into its purplish glory, and will soon be joined by the creamy white blooms of numerous Viburnum species, and the white flowers of shadbush and other Amelanchier species. For fall color, consider the intriguing yellow flowers of witchhazel or the red berries and yellow autumn foliage of fragrant spicebush.

With a few exceptions, most of the tree species already cited are native to Mid-Atlantic Piedmont and therefore dynamic parts of our overall ecosystem. In fact, one of the fastest growing motivations for tree planting is habitat restoration, the desire to help nature heal, at least in part. Selecting trees for our landscapes from this native palette ensures that they will thrive for decades to come. More importantly, planting these species helps to restore a small portion of the forest which once covered all of the Eastern United States.

Friend, invasive plant foe, and forest ecologist, Carole Bergmann frequently suggests the following as some of her favorite reforestation species for use in most upland planting areas: red maple, eastern red cedar, black gum, American hornbeam (which could also be used in a stream valley setting), red oak, white oak (the state tree), and tulip poplar. The poplar, incidentally, is a fast-growing tree, perfect for shade, although it is generally not a good idea to plant one next to a house, as branches can fall off during a storm.

For people planting trees in a stream valley location, watershed planner Craig Carson recommends American beech, green ash, river birch, and serviceberry, all of which are suited to the moister soils of the floodplain, and which further help to stabilize erosive soils and stream banks.

On a more mercenary note, some people plant trees to increase property values. A well-treed lot can often sell for 20 to 40 percent more than a bare yard. Of course, if your home only has one tree and some foundation plantings, to make a real difference you will have to plant more than just one tree, although that is always a good start. In effect, any true reforestation effort will require selecting approximately eight to ten different native species, possibly including some evergreens, and mixing both smaller, understory trees, with larger-growing canopy trees. Your personal forest will not pop up overnight, but it will be a delight to watch it grow and mature over the years to come. And perhaps that is one of the best reasons to plant trees, after all.

Monday, April 13, 2009

Nothing is as satisfying as lawn care. Coping with brown patch, powdery mildew, drought, rain and weeds. In return, you enjoy the weekly mowing, noisy machinery, fumes, sweating, raking leaves, watering, and the cost of buying seed and fertilizer. Ah, it’s the good life. Haven’t you had enough? Maybe instead of just cutting your lawn, you should cut it down to size.

To reduce overall lawn area, first remember that some grassy spots may be desirable for active recreational use. Leave room for your croquet set and badminton court. Any other unused areas, however, are prime candidates for reduction.

The magic word in shrinking lawn area is mulch. Mulch can be used to eliminate grass under trees and shrubs, which will protect them from damage and disease caused by mower and weed trimmers. The mulch can be placed under trees as far out as the end of the dripline: the area under the outermost branches. In addition to conserving moisture, the mulch will also emphasize the shape and natural beauty of these featured specimens.

Mulch can also be used to widen existing planting beds. Rather than having turf run right up to the edge of foundation plantings, such as azaleas, use a one or two foot wide layer of shredded bark to create a attractive margin between the lawn and shrubs, setting off both visual elements to their best advantage.

Applying mulch effectively, or using it to eliminate turf, requires a very simple trick. Rather than digging out clumps of grass or employing toxic chemicals to kill it, simply smother it. Use either newspaper or cardboard as a sublayer for the mulch. Flattened old cardboard boxes work well, and will not blow around like newspaper, which needs to be about 20 sheets thick. Either will provide an organic “blanket” to smother grass and weeds, and they will both decompose after several months.

Another option, albeit somewhat more costly, is to use landscape fabric, which is available in rolls ready for use, although you will probably want to remove or scrape down any grass first, for easier application. On the other hand, it is not advisable to use plastic as a mulch as it prevents necessary air and water from penetrating to plant root zones.

After setting the sublayer in place, start spreading your choice of organic mulch about four to six inches deep. No more grass, weeds, or mowing! Best of all, mulch is free, if you get it from the county, a local municipality or a tree care company, or generally inexpensive if you prefer a higher grade product, even when delivered in bulk. Above all, mulching is good for the long-term health of all your plants.

Ground covers are the next step in lawn reduction. Although they are a bit more expensive than mulch, they provide an enormous range of aesthetic values for every taste and landscaping situation. In fact, they are far less costly than turf in the long run. Once ground covers are in place, they will generally continue to spread and thrive without any help and with minimum annual maintenance. Try to say that about a lawn.

There are ground covers for sun and shade, dry and wet conditions, and they can fit almost every budget. Moreover, by pairing ground covers with mulch, you can actually save a substantial amount of money and cover a far larger area than you might have imagined possible.

For example, you might not want to have only a large circle of mulch under a favorite crepe myrtle in your front yard. With mulch and sixty dollars, you can underplant a fairly mature tree with white-flowering sweet woodruff. Realize, of course, that your container-grown plants will be spaced about a foot or so apart the first year, but each will quickly fill in to form a solid mass within a couple of years -- and they will keep on spreading! Mulch and patience, or at least time, are the secret to a healthy ground cover economy.

As another example, consider pachysandra, one of the most popular, albeit overused, shade-tolerant ground covers. A flat of some 80 to 100 plants will provide a thick, dense effect covering just under 12 square feet, if planted about four inches apart. However, by setting down a layer of mulch and planting the pachysandra about six inches apart, you will cover a 25 square foot area. Not as lush at first, although the mulch will help visually, but after a year or two, your planting will be every bit as rich looking at less than half the cost.

Another important place to look at eliminating grass is at the front of your property. Rather than having a bleak rectangle of lawn facing the street, why not frame your lawn with either a continuous bed -- or series of beds -- of evergreen ground covers? The border effect will transform your lawn from the dominant visual element into a less overwhelming component.

In sunny areas, using hardy, drought-resistant ground covers like creeping juniper or carpet cyprus can add a bold new dimension to your landscape. Again, first establish your planting area by setting down cardboard and mulch, and then plant your ground-hugging evergreens. Plants often come in one, two, or three gallon containers, ranging from six to 25 dollars.

Larger plants naturally cover an area more quickly, but with time even the smaller one gallon specimen will achieve a spread of eight to 15 feet. Imagine framing a 10,000 square foot lawn with this sort of a planting. It may take a number of years to fill in, but for about as little as $500, you can almost cut your lawn area in half.

To this scene, add a few specimen trees, with mulch, several ornamental trees and shrubs like native viburnums, redbud, and serviceberry, also planted in mulch beds, and the odd new planting bed or two with clumping native grasses and wildflowers, and a 10,000 square foot lawn monster can become a pleasant green ribbon easily managed with a push reel mower.

Shrinking your lawn may raise a few neighborhood eyebrows. It may even constitute landscaping heresy to those poor marketing victims who have been brainwashed into thinking that turf is worth any sacrifice of time, money, and resources. But the true measure of your landscaping acumen will come on a hot, hazy Saturday afternoon, as you rest in your shaded hammock, sipping a mimosa, quietly enjoying superior property values, a beautiful setting, and a healthier environment. Now that’s the good life!

Wednesday, April 08, 2009

Lawns can play an important part in our landscape: providing a welcome, green space for children, backyard barbecues, and other outdoor activities, in addition to their aesthetic value. Lawns also contribute significant environmental benefits: preventing erosion, nutrient runoff, filtering air, and providing natural "air conditioning" during the summer.

However, all of those advantages are lost when lawn care becomes warfare. When children and pets are at risk by crossing treated turf areas, or when sprays endanger the health of individuals who are immune-impaired or suffer from respiratory problems, we have to measure the real costs of lawn perfection. Are nodding violets, tasty spring onions, and edible dandelions so terrible that we're willing to imperil the health of ourselves and loved ones?

Instead of filling shopping carts with toxic solutions, we might borrow from theHippocratic Oath and first do no harm. When dealing with nature, less is almost always more. And the best system for lawn care is actually simple and inexpensive.

Mowing Tips

Mowing comprises about 95 percent of lawn care — yet mowers and cutting blades are the most overlooked elements of maintaining a healthy lawn.

Tune up your mower: Either do it yourself, or look for specials for professional tune-ups. An efficient engine will run smoother and faster, cut grass more quickly and evenly, and facilitate grasscycling by chopping grass into fine particles. It will also cause less air pollution, use less fuel, and save mowing time.

Sharpen your blade: Carefully remove the blade and bring it to a shop for sharpening (covered by most tune-ups). Consider buying an extra cutting blade to switch to during mid-season. Sharp blades provide a clean cut that will heal quickly. Dull blades rip and tear grass, opening vascular tissue to disease organisms. Poor cutting also results in lawns taking on a dull, brown appearance — which many lawn jockeys improperly try to correct by fertilizing!

Cut high: Taller grass will develop proportionally deeper, healthier roots, resist drought and summer heat, and prevent most broadleaf weed seeds from germinating. Fescues and Bluegrass should be cut no lower than 2-1/2 to 3 inches; Zoysia at about 1-1/2 inch.

Alter your mowing pattern: Do not use the same pattern or path to cut your lawn week after week. Periodically changing the direction in which you mow will help you avoid soil compaction.

A Proper Diet

Millions of advertising dollars are spent annually to sell fertilizers or "fertilizer programs," especially in the spring, when lawns have no need for supplemental nutrients. Overfeeding is a principal cause of turf disease. A quick jolt of nitrogen applied now will result in a wild burst of growth — and lots and lots of mowing! And the grass will be leggy and weak, unable to handle stress caused by changing temperatures and too much or too little rain. So hold off fertilizing until the fall, when it is appropriate!

Feed your lawn with clippings: When you grasscycle — leaving clippings behind when you mow — you're helping to recycle all of the free nutrients in every grass particle.

Watering

Improper and over-watering is another cause of lawn disease. Unless you are establishing a new lawn or overseeding, you don't need to water at all. Lawns thrive when roots are encouraged — and allowed — to grow deep. Watering creates a hydroponic zone at the top of the soil, making grass lazy and easy prey to drought and the scorching summer sun. Forget watering, and don't worry when fescues and other cool weather grasses brown out during the summer: dormancy is normal -- and inexpensive. Lawns will green-up when cooler temperatures and rainfall return. The environmental and economic cost of keeping a lawn green during the summer is staggering: hundreds of thousands of gallons of water for most lawns. Additionally, improper watering is a major culprit in fungal diseases, especially for folks who water in the evening. Of course, you can always buy fungicides — or you could just stop watering. Incidentally, overfeeding and overwatering are leading causes of thatch. So why bother?

Weeds

Homeowners have been sold an unrealistic picture of a healthy lawn. They expect a perfect monoculture, like a putting green. Weeds are never tolerated, although most of them have more right to be in our soils than the hybridized turf varieties we plant. A vast armada of herbicides is available, many with decidedly lethal brand names. And yet weed control can be chemical-free, for the most part. Perhaps the key ingredient is patience. The fact is that most weeds cannot compete or gain a foothold in a dense, healthy lawn. And weeds can be pushed out by grass — but it will take time. Nature thinks in glacial terms: seasons and years. There are no quick fixes.

Best First Steps

To grow the most vigorous lawn possible, there are certain steps to be followed:

Test your soil: Most states have local Cooperative Extension Service offices that offer soil testing for a nominal cost (usually around five to ten dollars). You can find your local city or county office online or in the phone directory blue pages. In addition, many garden centers also offer soil testing, although the costs are about ten times greater. But a soil test is one of the best investments you can make for your lawn. Test results will tell you exactly what to feed your lawn, how much lime to apply, when to apply those amendments, and much more. As many weeds grow in poor or acidic soils, you can make them go away just by correcting your soil's chemistry.

Aerate your lawn: It's a breath of fresh air for roots and soil, and one of the most recommended practices for relieving compaction, reducing thatch, and encouraging deep and extensive root growth — all of which will force out "undesirables." Some tough weeds, like plantain, will actually thrive in compacted soil — looser, aerated soils will resist such weed incursions. You can rent aerating machines or hire a lawn service.

Select the proper grass variety: Check with your local Cooperative Extension Service for advice on the best varieties of grass for your lawn, considering soil type, exposure, existing grass type, etc. The right grass for the right place will give you long-lasting results.

Make a salad: While you wait for weeds to naturally disappear, you can always hand- pick some of the tougher weeds. Many are edible (another argument against pesticides), while others are attractive and only last a short while. Be sure to remove bulbs, in the case of wild garlic and onions, the taproots of tasty dandelions, and as much of the rootstock as possible of other perennial or pernicious weeds.

Topdressing with organic matter: Instead of fertilizing this year, consider spreading1/4 inch of compost on lawn areas to further loosen heavy clay soils, break down thatch, and improve soil ecology.

Seed and overseed again: Getting soil in shape goes hand in hand with seeding to develop an increasingly dense lawn. Prepare soil and overseed in the Spring, or overseed after topdressing.

Why Not Relax?

Overall, you will find that working with your lawn is easier than working against it. Thebest, longest-lasting solutions are the simplest — although they are not the quickest.Balancing the value of human and environmental health against that of an award winning,chemically-dependent lawn, and you will probably decide to change some of your lawn care habits and put up with some weeds.

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About the GreenMan

I have been an environmental program director and educator for the past 25 years. I am also a writer, editor, columnist, and publisher, sometime producer, and off-and-on radio and cable television host.

The GreenMan? Beyond my educational background in Medieval Studies, and my personal interest in the image and myth of the "Green Man," I’ve taken on the term as a colorful bit of “branding” for my televised GreenMan Show and my long-running GreenMan newspaper column, which inspired many of the posts you find here.